Soft-tissue implants are used in various locations in the human body. The most common use is for reconstructing or improving the normal body contour or augmenting the female breast. The most common breast prostheses generally include a flexible elastomeric shell or envelope, typically made of silicone, which is filled with a soft gel, mainly silicone gel, a saline solution or a combination of both.
U.S. Pat. No. 3,683,424 discloses a compound prosthesis that has an elastic sack or envelope which contains an open-cells foam core and a quantity of a liquid in the cells of the core. The envelope has a flexible tube for adding the liquid at time of implantation so the size of the implant can be adjusted as desired.
U.S. Pat. No. 4,298,998 discloses a breast prosthesis claiming to overcome the tightness and contracture of the fibrous capsule which forms around an existing prosthesis. The construction of the prosthesis causes the capsule to form at a predetermined, controlled distance from the surface thereof. This prosthesis is constructed with a first phase or outer temporary component and a second phase or inner permanent component. The inner component is a container or sac of a flexible, non-absorbable material filled with a fluid or gel filler material. The temporary outer component is an outer container or cover of a material which is absorbable under the conditions of use, and an inert filler material, preferably an absorbable, biologically acceptable liquid, e.g. saline solution, filling the space between the inner and outer components.
U.S. Pat. No. 4,650,487 discloses a surgically implantable, multi-lumen, high profile mammary implant which includes a first, flexible, elastic lumen at least partly filled with a soft gel material and having a front wall approximating the shape of a human breast and a second, firmer, flexible lumen within the first lumen and connected thereto solely at the rear wall of the first lumen. A third lumen preferably inflatable surrounds the first lumen and is inflated with saline solution.
U.S. Pat. No. 5,236,454 discloses an implantable stacked breast prosthesis comprising two or more separate chambers stacked on each other, and fastened together eccentrically, so as to give a normal contour to the reconstructed or augmented breast and to prevent slippage of the chambers. At least one of the chambers is collapsed and may be variably filled with liquid.
U.S. Pat. No. 5,358,521 discloses a multi-layer prosthesis that simulates tissue tactility by structuring the plurality of layers of material making up the prosthesis to include lubricant coating between the layers. It is the plurality of layers and the lubricity of their movement which contributes greatly to the tactile simulation of human tissue. Present in the prosthesis is a ballast lumen which moves freely and contributes mass and motility to the prosthesis.
U.S. Pat. No. 5,376,117 discloses breast prostheses for subcutaneous implantation for breast augmentation. The prostheses include an outer shell having a smooth non-porous outer envelope and a non-woven porous outer layer affixed to the envelope.
U.S. Pat. No. 5,437,824 discloses a breast prosthesis for implantation beneath the skin. In one preferred embodiment the prosthesis has an outer elastic shell which encloses a biocompatible fluid and a silicone foam insert of unitary construction having the shape and approximate consistency and tactility of breast tissue. The foam insert occupies substantially the entire volume enclosed by the shell of the implantable prosthesis and consists of a foam body that is molded to the shape of the breast. In another preferred embodiment only a portion of the volume enclosed by the cell is occupied by the foam insert. In yet another embodiment a foam insert comprising an open-cell and closed-cell foam body may directly implanted beneath the skin for breast augmentation or reconstruction without a shell.
U.S. Pat. No. 5,824,081 discloses a tissue implant having visco-elastic characteristics which simulate the natural tissue that is intended to be augmented or replaced. The implant is comprised of a shell or envelope enclosing a compound foam body and a fluid filler material.
U.S. Pat. No. 6,187,043 discloses an implant and coverings for an implant for use in the human body. Coverings for implants are constructed to present a biocompatible surface to the body and to provide a textured surface which serves to disorganize scar tissue which forms around the implant.
U.S. Pat. No. 6,875,233 discloses a hinging breast implant capable a being variably sized and that includes an exterior shell and an inner bladder. The exterior shell is typically a bellows having a plurality of pleats so that the outer size of the implant is variable so that different sizes and shapes can be obtained. The inner bladder can be filled with a suitable filling material, liquid, gas or solid. As the bladder is filled, the exterior shell expands in a manner that creates a lifting effect and a ballooning effect.
U.S. Pat. No. 8,236,054 discloses an implantable soft tissue prosthesis comprising a hollow shell formed of a flexible elastomeric envelope, the shell having an inner volume and an exterior surface, when the inner volume is filled with an elastomeric silicone tubing that is preshaped conforming to the inner volume of the shell, the prosthesis being adapted to be surgically implanted in a human breast.
US 2002/0038147 discloses an improved permanently implantable breast tissue prosthesis comprising angularly and immutably attached base and dome envelopes wherein the base envelope is of a substantially triangular shape and the dome envelope is of a substantially discoid shape, each envelope having a shell defining an inner fluid containable chamber and an outer textured surface to be in direct contact with breast tissue and a valve formed as a part of a wall in base and dome envelopes, the valve facilitating the introduction, containment or removal of fluid within the containable chamber of each envelope.
US 2004/0162613 discloses a cosmetic and reconstructive prosthesis containing a rupture indicator, which includes an external envelope of medical grade elastomer containing a fluid material and a biologically compatible chemical indicator for indicating rupture of the prosthesis, and an internal envelope of medical grade elastomer disposed within the external envelope, the internal envelope containing an implant filling material.
WO 2007/000756, to the inventor of the present invention, discloses, inter alia, a human implantable tissue expander comprising a flexible enclosure for at least one material having at least one fluid flow characteristic; and a flexible and resilient skeleton associated with said flexible enclosure and being operative to maintain said flexible enclosure in a predetermined three-dimensional configuration generally independently of its orientation relative to gravitational acceleration.
WO 2008/081439, to the inventor of the present invention and others, discloses, inter alia, an implantable tissue expander including an internal skeletal element extending between a base surface and an outer surface and including at least one plurality of elongate cells extending along mutually generally parallel axes from the base surface to the outer surface and being defined by elongate cell walls formed of a resilient material; and a sealed enclosure, sealing the internal skeletal element and adapted for preventing body fluids from filling the plurality of elongate cells.
WO 2010/049926, to the inventor of the present invention, discloses, inter alia, a reconstructive breast prosthesis suitable for implantation into a void in a breast following a lumpectomy procedure in which a body of tissue is excised from the breast, the reconstructive breast prosthesis including an implant body at least generally configured to assume an implant shape corresponding to the shape of the body of tissue excised from the breast and an implant shape retaining structure adapted to maintain the implant body in the implant shape, the reconstructive breast prosthesis having an overall density which is less than the density of the body of tissue excised from the breast.
There still remains a need for improved implantable tissue expanders.